Chen Yu-Chen, Xia Wenqing, Chen Huiyou, Feng Yuan, Xu Jin-Jing, Gu Jian-Ping, Salvi Richard, Yin Xindao
Department of Radiology, Nanjing First Hospital, Nanjing Medical University, 210006, Nanjing, China.
Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University, 210006, Nanjing, China.
Hum Brain Mapp. 2017 May;38(5):2384-2397. doi: 10.1002/hbm.23525. Epub 2017 Jan 23.
The phantom sound of tinnitus is believed to be triggered by aberrant neural activity in the central auditory pathway, but since this debilitating condition is often associated with emotional distress and anxiety, these comorbidities likely arise from maladaptive functional connections to limbic structures such as the amygdala and hippocampus. To test this hypothesis, resting-state functional magnetic resonance imaging (fMRI) was used to identify aberrant effective connectivity of the amygdala and hippocampus in tinnitus patients and to determine the relationship with tinnitus characteristics. Chronic tinnitus patients (n = 26) and age-, sex-, and education-matched healthy controls (n = 23) were included. Both groups were comparable for hearing level. Granger causality analysis utilizing the amygdala and hippocampus as seed regions were used to investigate the directional connectivity and the relationship with tinnitus duration or distress. Relative to healthy controls, tinnitus patients demonstrated abnormal directional connectivity of the amygdala and hippocampus, including primary and association auditory cortex, and other non-auditory areas. Importantly, scores on the Tinnitus Handicap Questionnaires were positively correlated with increased connectivity from the left amygdala to left superior temporal gyrus (r = 0.570, P = 0.005), and from the right amygdala to right superior temporal gyrus (r = 0.487, P = 0.018). Moreover, enhanced effective connectivity from the right hippocampus to left transverse temporal gyrus was correlated with tinnitus duration (r = 0.452, P = 0.030). The results showed that tinnitus distress strongly correlates with enhanced effective connectivity that is directed from the amygdala to the auditory cortex. The longer the phantom sensation, the more likely acute tinnitus becomes permanently encoded by memory traces in the hippocampus. Hum Brain Mapp 38:2384-2397, 2017. © 2017 Wiley Periodicals, Inc.
耳鸣的幻听被认为是由中枢听觉通路中的异常神经活动引发的，但由于这种使人衰弱的病症常与情绪困扰和焦虑相关，这些共病很可能源于与杏仁核和海马体等边缘结构的适应性不良功能连接。为了验证这一假设，静息态功能磁共振成像（fMRI）被用于识别耳鸣患者杏仁核和海马体的异常有效连接，并确定其与耳鸣特征的关系。研究纳入了慢性耳鸣患者（n = 26）以及年龄、性别和教育程度相匹配的健康对照者（n = 23）。两组在听力水平上具有可比性。利用杏仁核和海马体作为种子区域的格兰杰因果分析，用于研究方向性连接以及与耳鸣持续时间或痛苦程度的关系。相对于健康对照者，耳鸣患者表现出杏仁核和海马体的异常方向性连接，包括初级和联合听觉皮层以及其他非听觉区域。重要的是，耳鸣障碍问卷的得分与从左侧杏仁核到左侧颞上回的连接增加呈正相关（r = 0.570，P = 0.005），以及从右侧杏仁核到右侧颞上回的连接增加呈正相关（r = 0.487，P = 0.018）。此外，从右侧海马体到左侧颞横回的有效连接增强与耳鸣持续时间相关（r = 0.452，P = 0.030）。结果表明，耳鸣痛苦与从杏仁核到听觉皮层的增强有效连接密切相关。幻听持续的时间越长，急性耳鸣就越有可能被海马体中的记忆痕迹永久编码。《人类大脑图谱》38:2384 - 2397，2017年。© 2017威利期刊公司。
